Donate Bitcoin

Donate Paypal


PeakOil is You

PeakOil is You

New Engine Could Boost Fuel Economy by Half

How to save energy through both societal and individual actions.

Re: New Engine Could Boost Fuel Economy by Half

Unread postby AdamB » Wed 10 Jan 2018, 12:32:07

aspera wrote:Ford hybrids also use the Atkinson cycle: https://en.wikipedia.org/wiki/Ford_Fusion_Hybrid
The Fusion Hybrid is a "full" hybrid because both propulsion sources, an electric motor powered by a Sanyo supplied 275 V nickel-metal hydride battery, and a 2.5L Atkinson cycle, 156 hp 136 ft.lbs. gasoline engine with intake variable cam timing (iVCT), have substantial power ratings and either can be used alone to propel the vehicle


Perhaps this is reference to the pre-2013 Ford Fusion models? The wife has the 2014 Energi model and it has the same drive train as the Ford 2013 Fusion hybrid, just the battery is bigger, and they are 2.0L engines, and lithium ion battery packs. And as the Energi model, it is an EV for about 20 miles at a time, which is entirely the mode she uses it in. As far as I'm concerned, it is a "true" hybrid, unlike the Gen I machines that couldn't run above 40mph without turning on the engine, needed the engine for A/C and heat, and most everything else. All they really did was coast really well under 40mph, and turn off at stop lights. Maybe they could move around a parking lot...slowly. Her Ford Energi can get right up to 75mph on all electricity, with the heat or A/C on, radio blasting, and do it all the way to work. She doesn't put any gasoline in the thing because, to her, it is fully functional as an EV.
Peak oil in 2020: And here is why: https://www.youtube.com/watch?v=2b3ttqYDwF0
AdamB
Volunteer
Volunteer
 
Posts: 4797
Joined: Mon 28 Dec 2015, 16:10:26

Re: New Engine Could Boost Fuel Economy by Half

Unread postby aspera » Wed 10 Jan 2018, 12:40:59

That's true. Second generation Ford hybrids were better (Fusion Gen 2 info below). We have a C-Max Energi (now discontinued as they bring out their new lines of PEVs). My spouse uses it around town and like yours stays mainly in EV mode (we live in a housing co-op with no way to plug it in right now, so charging happens elsewhere (e.g., at work, public parking sites with chargers).

[The second [Fusion] generation hybrid has a powertrain with a 2.0-liter Atkinson-cycle inline-four – downsized from the 2.5-liter unit used in the first generation Fusion Hybrid. Total output is estimated at 185 hp (138 kW) and 130 ft⋅lb (180 N⋅m), running to the front wheels via an electronically controlled continuously variable transmission. The lithium-ion battery pack saves weight and generates more power than previous NiMH batteries, and allows the second generation Fusion Hybrid to raise its maximum speed under electric-only power from 47 to 62 mph (76 to 100 km/h).
Oceans rise, empires fall.
Plant a garden. Soon.
User avatar
aspera
Peat
Peat
 
Posts: 140
Joined: Mon 28 Jul 2014, 16:22:49
Location: Lakeland Republic

Re: New Engine Could Boost Fuel Economy by Half

Unread postby Revi » Thu 11 Jan 2018, 13:44:02

I posted a pic of a Borque engine earlier. Any of these rotary engines seem like a better idea than the Otto Cycle engines we are using now. I saw an original Otto engine at the Owl's Head Transportation Museum last summer.

https://en.wikipedia.org/wiki/Otto_engine

Image

Image

The tragedy of the oil age is that we used about half of the oil on these inefficient engines, when we invented a lot of other kinds of engines way back in the 1800's and early 1900's.
Deep in the mud and slime of things, even there, something sings.
User avatar
Revi
Light Sweet Crude
Light Sweet Crude
 
Posts: 7304
Joined: Mon 25 Apr 2005, 02:00:00
Location: Maine

Re: New Engine Could Boost Fuel Economy by Half

Unread postby Outcast_Searcher » Thu 11 Jan 2018, 14:25:45

Revi wrote:The tragedy of the oil age is that we used about half of the oil on these inefficient engines, when we invented a lot of other kinds of engines way back in the 1800's and early 1900's.

If motor fuels had gotten expensive enough, for long enough, for motorists to truly highly prioritize fuel efficiency, auto makers would have gained a competitive advantage by offering seriously more efficient engines.

Now that vehicle electrification appears to be on the horizon to offer serious competition, AND global oil demand seems likely to keep upward pressure on oil prices as a long term trend (at least until EV production rivals that of the ICE) engine efficiency might finally get some serious attention.

Economics and capitalism in no way ensure optimal longer term solutions are chosen, as they aren't necessarily required for short to mid term profits to be realized.
Given the track record of the perma-doomer blogs, I wouldn't bet a fast crash doomer's money on their predictions.
User avatar
Outcast_Searcher
COB
COB
 
Posts: 7358
Joined: Sat 27 Jun 2009, 20:26:42

Re: New Engine Could Boost Fuel Economy by Half

Unread postby Tanada » Thu 11 Jan 2018, 14:40:46

I still think you would be better off with a nice simple 5 cylinder small radial, we have literally produced millions of these things and know how to make them run without a lot of new testing and development for your 4 cylinder Borque design. I know it is hard for an entirely new system to break through into production but small radials have been produced nearly as long as simple Otto inline engines. A two stroke version is well within our technical capabilities for the same reason it works for the Borque, it is all about how the piping is run and on a radial design it is a heck of a lot easier to run than on an inline design like those used in most ICE vehicles today.
Image
I should be able to change a diaper, plan an invasion, butcher a hog, design a building, write, balance accounts, build a wall, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, pitch manure, program a computer, cook, fight efficiently, die gallantly. Specialization is for insects.
User avatar
Tanada
Site Admin
Site Admin
 
Posts: 15583
Joined: Thu 28 Apr 2005, 02:00:00
Location: South West shore Lake Erie, OH, USA

Re: New Engine Could Boost Fuel Economy by Half

Unread postby kublikhan » Thu 11 Jan 2018, 16:42:44

Revi wrote:People have forgotten about the wankel
Mazda stopped making the Wankel because it had poor fuel efficiency and poor emissions - 2 areas automotive makers are paying more attention to.

The Mazda Wankel engines (a type of rotary combustion engine, specifically a Wankel engine) comprise a family of car engines produced by Mazda. Mazda rotary engines have a reputation for being relatively small and powerful at the expense of poor fuel efficiency. Mazda last built a car powered by a rotary engine in 2012, the RX-8, but had to abandon it largely to poor fuel efficiency and emissions. It has continued to work on the technology, however, as it is one of the company's signature features. Mazda officials have previously suggested that if they can get it to perform as well as a reciprocating engine they will bring it back to power a conventional sports car.
Mazda Wankel engine

Through the history of internal combustion engines, there has been plenty of evolution, but few revolutions. Talk of radically different designs always leads to a single name – Wankel. The Wankel rotary engine, most notably used in automobiles by Mazda, has been around since the late 1950’s. The Wankel rotary is an example of a design which makes sense on paper. However, practical problems cause it to underperform in the real world.

Reality sets in
So why aren’t we all driving Wankel-powered cars? The problem lies in the pitfalls of the design.

Fuel Economy: The Wankel’s combustion chamber is long, thin, and moves with the rotor. This causes a slow fuel burn. Engines try to combat this by using twin (leading and trailing) spark plugs. Even with the two plugs, combustion is often incomplete, leading to raw fuel being dumped out the exhaust port. The small 1.3 liter 232 horsepower two rotor engine in the 2011 Mazda RX-8 gets worse fuel economy (16 city / 23 highway) than the 6.2 liter 455 horsepower V8 engine used in the 2015 Corvette Stingray (17 city / 29 highway).

Emissions: The unburnt fuel, along with burned oil (described below) both result in terrible emissions from Wankel engines. The emissions problems are one of several reasons the RX-8 was pulled from production.

There is no way to keep the oil lubricating the seals out of the combustion chamber. Mazda engines include an injector pump which pushes small amounts of oil right into the engine housing, as well as into the air intake. This oil is eventually burned, causing increased carbon and emissions over the life of the engines.

Overhaul interval: Rotary engines in general don’t last as long as piston powered engines. As explained eloquently by Regular Car Reviews, the primary problem is with the seals. Browsing Mazda and rotary forums shows people rebuilding somewhere between 50,000 and 100,000 miles.

What does the future hold for the Wankel rotary engine? Most likely more of the same. Mazda will continue to support the engine, and it will continue to be used in some niche fields. However, it would take a major advancement in materials and design to correct all the issues that have thus far relegated the Wankel engine to a footnote in the history of internal combustion.
BROKEN PROMISES OF THE WANKEL ENGINE
The oil barrel is half-full.
User avatar
kublikhan
Master Prognosticator
Master Prognosticator
 
Posts: 4529
Joined: Tue 06 Nov 2007, 03:00:00
Location: Illinois

Re: New Engine Could Boost Fuel Economy by Half

Unread postby kublikhan » Sun 19 May 2019, 07:06:40

Well 7 years later and Delphi has completed the 3rd iteration of it's GDCI engine and is moving onto the 4th generation. The fuel efficiency improvement was there but other issues have prevented the engines from going commercial such as higher costs, higher emissions, durability issues, etc.

04-09-2019 - the lead researcher for a long-running, Delphi Technologies-directed program to maximize the thermal efficiency of gasoline engines said the latest developments show promise for delivering a production-ready gasoline engine that approaches 50% thermal efficiency. The improvements to the Gen3X engine further enhance the GDCI concept that has been under development in the $9.8-million U.S. Dept. of Energy-funded research program that began in 2011 and produced two prior versions of the engine. “All these engines are now obsolete,” Sellnau said flatly. “None meet the requirements for commercial light-duty engines.” Sellnau said numerous revisions have reduced the cost and complexity of the latest Gen3X engine and enhanced performance, not to mention durability.

The existing Gen3X engine, coupled to an 8-speed automatic transmission and a 12-volt start-stop system and fitted in a midsize passenger car, demonstrated 61 mpg fuel economy in the highway cycle and 48 mpg on the city cycle. Sellnau said the Gen4X engine is expected to be capable of 68 mpg on the highway.

On to a fourth generation
But despite meaningful gains in performance, efficiency and emissions reductions, Sellnau indicates the continuing research already is looking to the Gen4X engine. The research indicates that the GDCI engine can markedly exceed the efficiency of today’s best spark-ignited gasoline engines and hybrid-electric vehicles, which he said also are heavier and more complex.
Engine researchers: 50% gasoline-engine efficiency in sight

Hyundai ran into similar issues:
December 14, 2016 - Well, at this year's Hyundai powertrain-tech shindig, I got an update from powertrain honcho John Juriga as to just whatever happened to GDCI. He explained that under compression-ignition operating conditions, the peak cylinder pressures were so great that the block and lower end (crank and bearings) needed to be strengthened to what is essentially diesel specifications, adding cost and mass. All direct-injected gas engines have some issues with particulate emissions, and these were even worse with the GDCI engine, requiring a particulate trap not unlike what Mercedes is fitting to many forthcoming S-Class engines, which eroded the hoped-for emissions aftertreatment savings. The GDCI combustion process required considerable exhaust-gas recirculation, some of which was handled by retaining said gasses in the chamber using elaborate variable valve-timing mechanisms that added cost to the top of the engine. Achieving sufficient cylinder pressures at lower engine speeds demanded fitment of a supercharger in addition to the planned turbocharger, which added still more cost (and Juriga added that electric superchargers don't represent much of a savings relative to mechanical ones).

This litany of cost overruns left a less expensive, lower pressure direct fuel injection system as about the only remaining cost savings relative to a diesel, so the program was deemed too risky and expensive. We suspect Mercedes and GM have come to the same conclusion, as all has gone pretty quiet on the HCCI front.
WHATEVER HAPPENED TO HYUNDAI’S HCCI ENGINE?

Looks like Hyundai is trying again though:
Sep 24th 2018 - Hyundai said Monday it has won a grant worth $4.95 million from the U.S. Department of Energy to support research and development for an advanced, mixed-mode gasoline spark-compression engine, meaning the Korean automaker appears to be back at it in its quest to develop a fuel-efficient, low-emissions gasoline compression engine that can catch the likes of Mazda's Skyactiv-X.

Hyundai says the three-year grant will leverage existing work with advanced valve train and previous DOE-funded technologies. Hyundai previously was working on its own HCCI — short for homogeneous charge compression ignition — project, developing a Gasoline Direct-Injection Compression engine with help from Delphi that used supercharging and turbocharging, a high compression ratio and fully variable valve train. But it has never come to fruition, reportedly due in large part to added costs.

Hyundai spokeswoman Michele Tinson said the grant will support a new project for the automaker. "It's a departure from the past efforts forging a new direction forward for Hyundai where the fuel and engine combustion modes can be optimized to meet new targets." Tinson said the GDCI project is completing its third round of DOE funding.
Hyundai returns to spark-compression engines with $5 million grant

Mazda had to push back it's compression engine as well and the 2019 Mazda 3 has a more conventional engine. Apparently Mazda took the route of using the efficiency savings to produce an engine of equal power but smaller fuel consumption. This made sense when gasoline prices were expensive and US consumer were downsizing. However with cheap gasoline and the US consumer opting for larger vehicles, Mazda wants to tweak the engine to produce more power output as they feel the higher fuel efficiency alone is not enough of a selling point in the current market.
1/28/19 - I was pretty impressed with the short amount of time in the 2019 Mazda 3. But besides wondering when we’ll get the all-wheel drive hatchback with a manual, there was one huge question on my mind: “Where’s the ‘holy grail’ SkyActiv-X engine on this car?” So I asked around. While there’s no word on exactly when we’ll see the X engine make it into the new 3, Moro did clue us into what the hold-up could be about.

Mazda told Jalopnik the company is still exploring the SkyActiv-X technology for its full potential. As it stands, the initial excitement over the new technology was its improved and more reliable efficiency gains over the SkyActiv-G engines. But its efficiency in combustion also has the potential to produce more power compared to a normal gasoline engine of similar displacement.

This could be where Mazda’s focus for the engine is at now. Moro mentioned that the company is fine-tuning the engine in preparation for production, and that he believes the engine needs to do more than just get better fuel efficiency, since gas prices are low and it would be tougher to market it on fuel savings alone.

The suggestion is that Mazda is now working to tune as much performance out of the engine as possible, possibly even with turbocharging. When we previously drove a prototype back in September of 2017, the 2.0-liter SkyActiv-X could produce 187 horsepower—as much as the 2.5-liter SkyActiv-G engine in the 2019 Mazda 3. If Mazda can push that level of performance enhancement higher, then it has a new way of marketing its fancy new engine.
Here's Why the 2019 Mazda 3 Doesn't Have the 'Holy Grail' Skyactiv-X Engine Yet
The oil barrel is half-full.
User avatar
kublikhan
Master Prognosticator
Master Prognosticator
 
Posts: 4529
Joined: Tue 06 Nov 2007, 03:00:00
Location: Illinois

Re: New Engine Could Boost Fuel Economy by Half

Unread postby asg70 » Sun 19 May 2019, 08:23:40

We may see these engines but internal combustion is definitely at the law of diminishing returns. Electrification has to pick up the slack, and frankly it already has been since the original Prius over 20 years ago.

HALL OF SHAME:
-Short welched on a bet and should be shunned.
-Frequent-flyers should not cry crocodile-tears over climate-change.
asg70
Intermediate Crude
Intermediate Crude
 
Posts: 3021
Joined: Sun 05 Feb 2017, 13:17:28

Re: New Engine Could Boost Fuel Economy by Half

Unread postby AdamB » Sun 19 May 2019, 13:17:23

asg70 wrote:We may see these engines but internal combustion is definitely at the law of diminishing returns. Electrification has to pick up the slack, and frankly it already has been since the original Prius over 20 years ago.


I think it is a fair bet that the ICE might be on its last legs for all sorts of reasons, let alone an obvious one like once you drive a full on EV, anyone with a shred of gee-whiz in their bloodstream can feel it activate under acceleration. Peak oilers can love it for its peak oil solution personal transport aspects, beyond not putting liquid fuel in my transport, it is even better that I can fuel it in my garage.
Peak oil in 2020: And here is why: https://www.youtube.com/watch?v=2b3ttqYDwF0
AdamB
Volunteer
Volunteer
 
Posts: 4797
Joined: Mon 28 Dec 2015, 16:10:26

Re: New Engine Could Boost Fuel Economy by Half

Unread postby Revi » Tue 11 Jun 2019, 11:16:39

AdamB wrote:The Atkinson is fine, but even combined with a big battery pack to provide the torque, the mileage increase isn't all that big. We are still talking about cars that get less mileage than things like the 1980's vintage Honda CRX-HF or even my old stripped down 1986 Honda Civic with a 4 speed in it.

I agree. I look at mileage from those 80's Hondas, and they are almost as good as a Prius. Why aren't we back to that kind of mileage in a regular car?
Deep in the mud and slime of things, even there, something sings.
User avatar
Revi
Light Sweet Crude
Light Sweet Crude
 
Posts: 7304
Joined: Mon 25 Apr 2005, 02:00:00
Location: Maine

Re: New Engine Could Boost Fuel Economy by Half

Unread postby Tanada » Tue 11 Jun 2019, 13:28:03

Revi wrote:
AdamB wrote:The Atkinson is fine, but even combined with a big battery pack to provide the torque, the mileage increase isn't all that big. We are still talking about cars that get less mileage than things like the 1980's vintage Honda CRX-HF or even my old stripped down 1986 Honda Civic with a 4 speed in it.

I agree. I look at mileage from those 80's Hondas, and they are almost as good as a Prius. Why aren't we back to that kind of mileage in a regular car?


It is mostly about the weight. To make happier customers out of Americans they added much more comfortable seats, and power windows, and power door locks, and A/C compressors and air bags and...and...and...

After adding all those luxury items that dragged the weight of the vehicle way up they needed a bigger engine to get the necessary horsepower and torque, and that weighs more as well, and a bigger fuel tank to maintain your 350-400 mile range on a fill up.

Net result, your 2019 Honda civic is as comfortable as a 1989 Ford Mercury sedan, and about the same size. Your 1989 Honda Civic would be considered a sub-compact car in todays world. When my spouse needed a new car and bought a 2012 Honda Civic and parked it next to my 2000 Honda Civic the size difference was astounding!

2019 Civic Specs wrote:Body
Body Style: Sedan
Dimensions
Wheelbase (in.): 106.3
Length, Overall (in.): 182.7
Width, Max w/o mirrors (in.): 70.9
Height, Overall (in.): 55.7
Doors & Windows
Rear Defrost
Power Windows
Doors & Windows
Rear Defrost
Power Windows
Exterior Features
Sun/Moon Roof
Sun/Moonroof
Rear Spoiler
Measurements
Base Curb Weight (lbs.): 2917


1989 Civic wrote:Body Style
Sedan
Dimensions
Maximum Seating 5 seats
Fuel Tank Volume 11.9 gal
Front Legroom 43 in
Back Legroom 32 in
Wheelbase 98.4 in
Length 166 in
Width 65 in
Height 53 in
Curb Weight-manual 2147 lbs
Engine
1.5L 92 hp I4
I should be able to change a diaper, plan an invasion, butcher a hog, design a building, write, balance accounts, build a wall, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, pitch manure, program a computer, cook, fight efficiently, die gallantly. Specialization is for insects.
User avatar
Tanada
Site Admin
Site Admin
 
Posts: 15583
Joined: Thu 28 Apr 2005, 02:00:00
Location: South West shore Lake Erie, OH, USA

Re: New Engine Could Boost Fuel Economy by Half

Unread postby KingM » Wed 12 Jun 2019, 10:55:43

Your 2019 Civic is far more comfortable than pretty much any standard 1989 car.
User avatar
KingM
Tar Sands
Tar Sands
 
Posts: 731
Joined: Tue 30 Aug 2005, 02:00:00
Location: Second Vermont Republic

Re: New Engine Could Boost Fuel Economy by Half

Unread postby Outcast_Searcher » Sun 16 Jun 2019, 19:32:22

Tanada wrote:
Revi wrote:I agree. I look at mileage from those 80's Hondas, and they are almost as good as a Prius. Why aren't we back to that kind of mileage in a regular car?


It is mostly about the weight. To make happier customers out of Americans they added much more comfortable seats, and power windows, and power door locks, and A/C compressors and air bags and...and...and...

It is mostly about the weight. And no doubt, Americans crave fancier cars with more gadgetry.

But the added weight is partly about evolving safety standards too.

As you say, airbags aren't weightless. Neither as side impact door beams, etc. etc.

What it's not is some kind of conspiracy. It's trade-offs. Hopefully when Trump isn't in office, the push toward higher CAFE standards will dominate, and the fleet will continue to fairly rapidly get more fuel efficient. Aided by electrification including HEV's, of course.
Given the track record of the perma-doomer blogs, I wouldn't bet a fast crash doomer's money on their predictions.
User avatar
Outcast_Searcher
COB
COB
 
Posts: 7358
Joined: Sat 27 Jun 2009, 20:26:42

Re: New Engine Could Boost Fuel Economy by Half

Unread postby kublikhan » Tue 18 Jun 2019, 13:32:04

Mazada's SPCCI engine is said to be coming to Europe and Japan in the Mazda 3 this fall. SPCCI sounds pretty similar to a how a standard gasoline engine achieves ignition: with a spark plug. Not really sure if that should be called compression ignition then? But it does have a nice fuel economy boost, going from a combined 31 mpg for the current Mazda 3 to 44 mpg, although probably around a third of that fuel economy savings is from the mild hybrid system.

Mazda’s SkyActiv-X powertrain, set to be the first production compression-ignition gasoline engine. SkyActiv-X (pronounced “ex” not “ten”) is the powertrain side of the next iteration of Mazda’s continual push to cut its corporate average emissions ratings while boosting fuel economy. Today’s engine families are called SkyActiv-G and SkyActiv-D, for gasoline and diesel, respectively. Compared to SkyActiv-G, X is intended to improve fuel efficiency by 20-30 percent while also boosting torque 10-20 percent, relative to today’s 2.0-liter engine. Today’s Mazda 3 2.0-liter automatic hatchback, for instance, produces 155 horsepower and 150 pound-feet of torque, and returns EPA figures of 28 miles per gallon city and 37 mpg highway.

The secret to this new performance is gasoline compression ignition, which harnesses many of the benefits that diesel engines have enjoyed for years. Normal gasoline engines set fire to a mixture of fuel and air, which expands throughout the cylinder and forces the piston down. But by squeezing a very lean mix of air and gasoline until it explodes spontaneously, like in a diesel engine, Mazda engineers say the SkyActiv-X engine can produce more torque, waste less heat, and use less fuel overall. Many automakers have explored the idea, but no one has been able to get it ready for a production model – until now. Essentially, more power is produced over a shorter period of time each time, because compression ignition is much more violent than simply lighting an air-fuel mixture. Mazda research and development engineer Jay Chen likens it to popping an inflated balloon instead of simply letting the air out through the neck.

Most of the time, the engine runs in what Mazda calls Spark Controlled Compression Ignition (SPCCI) mode. A very lean mix (i.e., there’s a high proportion of air to gasoline) is ingested in the compression stroke, swirling around thanks to a special piston design; the supercharger is used to add extra air if needed to thin out the mixture. Then right as the piston reaches top dead center, with that mix almost ready to ignite of its own accord, the engine sprays in another small amount of fuel and ignites it with a spark plug. That explosion pushes the remaining air-fuel mix over the edge into an explosion, producing lots of power very quickly. That was Mazda’s innovation: using a spark plug to kick-start compression ignition. Otherwise, engineers say, it’s very difficult to get the explosion to happen at precisely the right time. To keep tabs on the whole process, pressure sensors in each cylinder give feedback to the engine computer: “Only now are our engine control processors fast enough to control this event by event by event.”

Other times, however, the Mazda engine runs like a regular spark-ignition engine. It switches to this mode primarily in high-load, high-RPM running; for performance, in other words, compression ignition still won’t do the job. But because the engine always uses a spark plug all the time, engineers say the engine can “seamlessly” alternate between the two running modes.
Mazda SkyActiv-X Prototype First Drive: The Future Of Gas Engines?

Mazda now confirms the official European specs for its highly anticipated Skyactiv-X engine in the Mazda3. The 2.0-liter four-cylinder powerplant makes 177 horsepower (132 kilowatts) and 165 pound-feet (224 Newton-meters) of torque. Deliveries of the Mazda3 with the new mill begin in the fall, and pricing isn't available at this time. The Skyactiv-X engine in the Mazda3 also comes standard with a 24-volt mild hybrid system. The tech is able to harvest energy during deceleration and releases it to boost fuel economy. At its best in the six-speed manual, front-wheel-drive sedan, the Skyactiv-X engine delivers 5.4 liters per 100 kilometers combined fuel economy in the WLTP test. This figure is roughly equivalent to 44 miles per gallon, but it's worth noting that the American EPA evaluation is different, so the Mazda3 with this mill would not have an identical rating in the United States.

The Skyactiv-X engine is capable of running both on spark-controlled ignition, like most gasoline-fueled vehicles, and compression ignition, like a diesel. While the mill arrives in Europe and Japan soon, Mazda isn't yet saying when or if the powerplant is coming to the U.S.
Mazda Skyactiv-X 2.0L Engine Confirmed With 178 HP, 165 lb-ft
The oil barrel is half-full.
User avatar
kublikhan
Master Prognosticator
Master Prognosticator
 
Posts: 4529
Joined: Tue 06 Nov 2007, 03:00:00
Location: Illinois

Re: New Engine Could Boost Fuel Economy by Half

Unread postby Carnot » Mon 01 Jul 2019, 05:26:56

This reply is merely to correct an very significant error in the cut and paste text of the previous posting. The Mazda Sky active is an ICE- meaning internal combustion engine, not an internal explosion engine as the writer suggests. Were the fuel air mixture to explode that would create pressures and shock waves that would destroy an engine in short order. Combustion engines rely on the fuel and air mixture burning at a subsonic rate causing a progressive rise in pressure, ideally with much of the burning occurring before TDC. Thus on the expansion stroke more of the contained energy in the fuel is transferred to the crankshaft. Burning post TDC results in less power and increases thermal losses in the exhaust, as the fuel energy is not captured as well during expansion.

Actual flame speeds are quite low. The burning speed is typically <10 m/s, and the laminar flame speed < 2m/s. Information from Internal Combustion Engine Fundamentals p 409-410. There are situations where an explosion can occur in both diesel and spark ignition engines, and is accompanied with a metallic pinging noise due to the shock waves and pressures, as corresponding loss of power.

Light distillate fuels. ie. gasoline are not optimised for compression ignition, unlike diesel fuels. High octane number in effect raises the autoignition point of gasoline to in excess of 300 deg C, whereas as diesel fuels, including kerosine, will autoignite in the area of about 220 deg C. Previous attempts to use light distillate fuels in a compression ignition engines was not successful. This technology was known as HCCI (homogenous charge compression ignition). Much of the problem was due to the high autoignition temperature of gasoline. Reformulating the fuel to a more diesel like make up with a lower autognition point would have required a completely new fuel type. This though technically possible would be commercially challenging requiring tanks and pumps in the filling stations.
Carnot
Expert
Expert
 
Posts: 153
Joined: Wed 07 Aug 2013, 09:54:16
Location: Europe

Re: New Engine Could Boost Fuel Economy by Half

Unread postby AdamB » Mon 01 Jul 2019, 09:53:05

Carnot wrote:This reply is merely to correct an very significant error in the cut and paste text of the previous posting. The Mazda Sky active is an ICE- meaning internal combustion engine, not an internal explosion engine as the writer suggests. Were the fuel air mixture to explode that would create pressures and shock waves that would destroy an engine in short order. Combustion engines rely on the fuel and air mixture burning at a subsonic rate causing a progressive rise in pressure, ideally with much of the burning occurring before TDC. Thus on the expansion stroke more of the contained energy in the fuel is transferred to the crankshaft. Burning post TDC results in less power and increases thermal losses in the exhaust, as the fuel energy is not captured as well during expansion.

Actual flame speeds are quite low. The burning speed is typically <10 m/s, and the laminar flame speed < 2m/s. Information from Internal Combustion Engine Fundamentals p 409-410. There are situations where an explosion can occur in both diesel and spark ignition engines, and is accompanied with a metallic pinging noise due to the shock waves and pressures, as corresponding loss of power.

Light distillate fuels. ie. gasoline are not optimised for compression ignition, unlike diesel fuels. High octane number in effect raises the autoignition point of gasoline to in excess of 300 deg C, whereas as diesel fuels, including kerosine, will autoignite in the area of about 220 deg C. Previous attempts to use light distillate fuels in a compression ignition engines was not successful. This technology was known as HCCI (homogenous charge compression ignition). Much of the problem was due to the high autoignition temperature of gasoline. Reformulating the fuel to a more diesel like make up with a lower autognition point would have required a completely new fuel type. This though technically possible would be commercially challenging requiring tanks and pumps in the filling stations.


Thanks for the info! Good stuff! [smilie=3some.gif]
Peak oil in 2020: And here is why: https://www.youtube.com/watch?v=2b3ttqYDwF0
AdamB
Volunteer
Volunteer
 
Posts: 4797
Joined: Mon 28 Dec 2015, 16:10:26

Previous

Return to Conservation & Efficiency

Who is online

Users browsing this forum: No registered users and 3 guests

cron